Apparatus for cleaning plate-glass-grinding tables or cars



Dec. 14., 1926. 1,610.374

H. SfHElCHERT ET AL APPARATUS FOR CLEANING PLATE GLASS GRINDING TABLES0R CARS Filed March 18 L925 3 Sheets-Sheet 1 but a v m fij Dec. 14,1926. 4 1, 10,374 I H. S. HEI CHERT ET AL APPARATUS FOR CLEANING PLATEGLASS-GRINDING TABLES on CARS Filed March 18. 1925 Sheets-Sheet 2 25 23i 1a 1a INVENTOR #QWQ 1925 3 Sheets-Shes? 5 INVENTOR 5% H. s. HEI'CHERTET AL Filed March 18 Dec. 14 1926.

APPARATUS FOR CLEANING PLATE GLASS GRINDING TABLES 0R CARS Patented-Dec.1.4, 1926.

UNITED STA TES PATENT OFFICE-- HERMAN HEIGHERT AND ALBERT E. S, 0FPITTSBURGH, PENNSYLVANIL AS SIGNORS TO PITTSBURGH PLATE GLASS COMPANY, ACORPORATION OF PENN SYL- VAiN IA.

APPARATUS FOR CLEANING PLATE-GLASS-GRINDING TABLES OR CARS.

Application filed fiarch 1a, 1925. Serial u 16,469.

The invention relates'to apparatus for removing the plaster from plateglass supporting tables or cars suchas are employed in a straight awaygrinding and polishing operation recently developed in this country.

The glassislieets' are secured to the tops of the tables by plaster ofParis and after the. sheets have been ground and polished and "priedloose from the plaster, it becomes necessary to remove the layer ofplaster remainin preliminar to tie application of anot er sheet.complished by hand labor, the workers climbing upon the tables withscrapers and poundingfand scraping the surfaces of the car to remoye therelatively hard adherent plaster} The difficulty of the operation isincreased by the woo holding pegs which are arran ed in series alongeach side of the car with their upper ends projecting slightly above thesurface of the car. These pegs prevent the scrapersfrom sliding clear tothe edges of the tables so that it becomes necessary to drive each onedown so that its top is flush with the top surface of the table, whichoperation takes considerable time and effort. The present invention isdesi ned to provide-for the removal of the hard ayer of plaster withouthand labor and also to automaticall drive the pegs down out of the wayso t at the table is completely freed from plaster from edge to edge. Itis further designed to accomplish this result without cutting or wearingaway the tops of the cars or tables, being so arranged that a thin filmof protecting plaster is left on the surface of each car. This film ofplaster has been found to give a firmer connection with the freshplaster which is applied than was secured between.-the table tops andthe fresh plasten when the film was completely removed'so that thedanger of the sheets becoming loosened during the subsequent grindingand polishing operation is materially reduced. In carrying out theoperation, a brush made up of metallic strips or fibers is referablyemployed (although some other orm of cutter might be used) for cuttingaway the plaster, and the life of this cutting member and also that ofthe holding pegs is greatly increased by the expedient'of forcing downthe pegs preliminary tothe application of the cutter. It has also beenfound desirable to apply scraper eretofore, this has been acmeans bothin front'of and behind the cutting brush, the one in advance serving toclear away any broken glass or other detritus left on the surface of theplaster, and the one following the brush serving to wipe away any looseplaster left after thecutting operation, the latter function beingfacilitated by a plying a flow of water along the scraper. isillustrated in the accompanying drawings wherein:

Figure 1 is a sectional plan vie-w of the apparatus. Fig. 2 isasectional side elevation. Fig. 3 is-a sectional rear elevation. Fig. 4is a front elevation. Figs. 5 and 6 are enlarged detail elevations ofthe laster crushing and peg pushin devices, ig. 5 being a side elevationand Fig. 6 being a plan view. Fi 7 is an enlarged section on neembodiment of the invention rack bars 6 secured to the bottoms of the Icars or tables. The spurgears are them selves rotated from the driveshafts 7 by meansof pinions 8.meshing with such spur gears. The track 4is a continuation of the track u on which the cars are carried be.-neath t e grinders and polishers and the cars are moved beneath such.grinders and polishers by operating means, of which the parts 5, 6, 7and 8 constitute a unit.

9 are the wood pegs arranged in series along each side of the tables andcars and serve as positive means for holding the glass on the tablesagainst lateral movement. These pegs have a driving fit in the openingsextending through the metal table tops so a tri e belowthe top surfaceof the glass. 4

. taneously crushing the plaster 13 (Fig.

along the sides of the tables and surrounding the pegs. The devices forautomatically accomplishing this purpose as the tables move alongconsist of a pair -of shoes or cams 14 having their lower surfacesrounded as indicated at 15 and secured by means of the bolts 16 to theyokes 17. The yokes 17 are supported from the transverse beam 12 bymeans of brackets 18 to which the yokes are pivoted by means of the rods19.

The other ends' of the yokes are pressed yieldingly downward by means ofsprings 20 bearing upon the yokes and held under compression by means ofthe nuts 21 upon the vertical threaded rods 22. These rods [extendthrough brackets 23 bolted to the beam 12. They are threaded intosleeves 24 fitting into the brackets and each sleeve may be rotated tomove the-rod up and down and so adjust thetension of thespring 20 bymeans of the nut 25 keyed to the upper end of the sleeve and providedwith the handle 26. Lock nuts 27 and 28 serve .to fix the positionsofthe nuts 25 and 21 respectively. By this means the pressure of theshoes can be adjusted to. exactly the right amount in order to crush theplaster and push the pins down'and at'the same time not exert an undueamount of pressure on the table tops. The" shoes 14 thus serve to breakup the plaster at the edges of the table and press the pins 9 down sothat the cutter device (the brush as later described) can properlyperform its function of cleaning the table throughout its width and alsore u ce the Wear upon the brush and pins such as would be involved ifthe pins were not pressed down out of the way. The shoes constitute onlyone of a number of possible devices that might be employed foraccomplishing the desired function, such shoes, however, constitutingthebest means so far developed for performing. this function.

Mounted on opposite sides of the track are a. pair of standards 29 and30 for supporting the transverse frame 31 upon which the rotatin cutterbrush 32 is" mounted. This frame is pivotally supported at one end uponthe pivot rod 33 carried'by the stand-' ard 29, while the other end ofthe frame is releasably supported upon the standard 30 by bolts (notshown) so-that'upon the release of the frame from the standard 30,

it may be swung around the pivot rod this. being a desirable arrangementunder certain conditions. The frame is provided with a pivot shaft 34upon which are mounted the swinging arms, 35 and 36 in which the endsofthe brush 32 are journalled. The arm 35 has an extension or platform37 on the opposite side of the shaft 34 on which is mounted the motor 38for driving the brush 32 through the intermediary of a pair of sprocketwheels 39 and 40 on the ends of the motor shaft and brush shaftrespectively and the sprocket chain 41.

The brush is made up of radial fibers in the form of light metal stripswhich have an abraiding effect upon the plaster on the table when thebrush is driven at' a high.

rate of speed, and means are provided for adjusting the pressure of thebrush upon the plaster so that just the right amount of cutting pressuremay be exerted in order to cut away the major portion of the plaster,leaving the thin film heretofore referred This method of procedure notonly prevents the gradual Wearing away of the top surface of the table,such as would occur if the entire layer of plaster were cut away, butit. has also been found that there is less tendency of the glass sheetsto loosen during the grinding and polishing operationwhen the freshplaster is laid upon a film of plaster than is the case when the freshplaster is applied directly to the metal llll) table tops. The adjustingdevice for the brush comprises a bracket 42 secured to the bottom of the'motor support 37 and the threaded rod 43' extending through the hub 44integral with the standard 29 and adjustable by means of the hand wheel45 provided with a suitable nut. A spring 46 is interposed between theend of the bracket 42 and the bottom of the hub 44 which serves to movethe brush upward as the nut 47 is unscrewed.

In order to remove any loose glass or other detritus on the forward sideof the brush, a wood scraper 48 is employed, (see Fig. 7) such scraperbeing supported by means of suitable brackets 49 and 52 secured to theframe 31. A flow of water over the surface of the table onthis side ofthe brush is also provided from the pipe 50,. the purpose being tosoften the plaster preliminary to the action of the cutting brush. Ascraper 51 is also provided on the other side of the brush in order toclean the surface of the tables from loose plaster left by the action ofthe brush. This scraper is also supported from the frame 31 by means ofthe brackets 52 and 55 and a pair of rubberstrips 53 between which Iwater is supplied-from a pipe 54. The brackets 49, 52 and 55, abovereferred to,- for supporting the scrapers are preferably in the form ofbars or strips of metal arranged at" spaced intervals and bolted to theframe 31; This gives an effective cleaning ofithe table tops and placesthem in condition so that they are ready for the appliacross the tablesbehind the cutter device,

and means positioned at one side of the tables for directing a supply ofwater across the tables along the side of said scraper means.

2. Apparatus for cleaning plaster from tables mounted for movement alonga track,

comprising a cutter device mounted for rotation above the track andadjusted so that it will cut away the major portion of the plaster uponthe tables leaving .a thin film remaining on the tables, power means forrotating the cutter device, and scraper means located across the tablesin front of said cutter-device and behind such device.

3. Apparatus for cleaningv plaster from tables mounted for movementalong a track, comprising a rotary brush extending across the 'track andprovided with radially ex tending metallic fibers, an adjustable tiltingframe carrying the brush and power means for rotating the' brush at ahigh rate of speed so as to cut the plaster from the tables as they passbeneath the brush, said power means being supported from said'frame;

4. Apparatus for cleaning plaster from tables mounted for movement alonga track and provided along each side with vertically movable glassholding pegs projecting above the surfaces of the tables, comprising acutter device mounted above the tables so as to engage the plasterthereon as the tables move beneath such cutter and a cam device on eachside of the tables in advance of the cutter adapted to engage and crushthe plaster along the sides of the tables and to force the holding pegsdownwardso that their upper ends are flush with'the surfaces of thetables.

5. Apparatus for cleaning plaster from tables mounted for movement alonga track and provided along each side with vertically movable glassholding pegs projecting above the surfaces of the tables, comprising apower driven cutter device mounted for-ro tation above the track, andadapted .to cutaway the'plaster on the tables and the pass therebeneath,and a cam device on each. side i of the tables in advance of the cutteradapted to engage and crush the plaster along the -sides of the tablesand to force the holding pegs downward so that their upper ends areflush with the surfaces of the, tables;

6. Apparatus for cleaning plaster from tables mounted for movement alonga track and provided along each side with vertically movable glassholding pegs projecting above the surfaces of the tables, comprising acutter device mounted above the tables so as to engage the plasterthereon as the tables move beneath such cutter, and a shoe on each sideof the tables in advance of the cutter" .7. Apparatus for cleaningplaster from tables mounted for movement along a track and providedalong each side with vertically movable glass holding pegs projectingabove the surfaces of the tables, comprising a cut- I ter device mountedabove the tables so as to engage the plaster thereon as the tables movebeneath such cutter,*and a shoe on each side of the tables in advance ofthe-cutter i yieldingly pressed downward and having its forward endinclined upward and adapted to ,engage and crush the plaster along the Isides of the tables and to force the holding movable glass holding pegsprojecting above the surfaces of the tables, comprising a cutter devicemounted above the tables so as to engage the plaster thereon as thetablesmove beneath such cutter, a cam device on each side of the tablesin advance of the cutter adapted to engage and crush the plaster alongthe sides of the table and force the pegs downward, yielding means forpressing such devices downward, and means for adjusting the pressure ofsaid yielding means. 9. Apparatus for cleaning plaster from tablesmounted for movement along a track and provided along each side withvertically movable. glass holding pegs projecting above the surfaces ofthe tables, comprising a presser device on each side of the tables abovetheside edges of the tables, adapted to engage and crush the plasteralong such side edges and to force the holding pegs downward so thattheir upper ends are flush with the surfaces of the tables. I

10. Apparatus for cleaning plaster fron tables mounted for movementalong a track and provided along each side with vertically movable glassholding pegs pro ect1ng above the surfaces of the tables, comprising apresser device on each side of the tables above the side edges of thetables, and yielding means for forcing such devices downwardso that theyengage and crush the plaster along such side edges and force the holdingpegs downward so that their upper ends are flush with the surfaces ofthe tables.

11. Apparatus for cleaning plaster from tables mounted for movementalong a track and provided along each side with vertically movable glassholding pegs projecting above the surfaces of the tables, comprising apresser device on each side of the tables above the side edges of thetables, yielding means for forcing such devices downward so movableglass holding pegs projecting above the surfaces of the tables,comprising a shoe on each side of the tables above the side edgesthereof and" having its forward end turned up, adapted to enga 'e andcrush the plaster along such side edges and to force the holdingpegs'downward so' that their upper ends are flush with the surfaces ofthe tables.

13. Apparatus for cleaning plaster from tables mounted for movementalong a track, comprising a frame extending transversely across thetables and pivotally supported at one end so that it may be swunglaterally to bring it to one side of the tables, a brush mounted forrotation in the frame and provided with radially extending metallicfibers adapted to cut the plaster when the brush is rotated at a highrate of speed, and a motor also mounted upon the frame and havingdriving connection with the brush.

Intestimony whereof, we have hereunto subscribed our names this 16th dayof March, 1925;

S. E. EVANS.

